Human β-defensin-3gene expression in mucosa of ORL organs

Abstract

The aim of present study was to investigate the hBD-3 gene expression in the surface epithelium of mucosa in ORL organs. We have studied a total of 210 mucosal samples, obtained at the most frequent surgical intervantions from 5 different anatomical functional areas: nose and paranasal sinuses, middle ear, nasopharynx, oropharynx, larynx. The inferior turbinate mucosa (1) and the normal middle nasal passage mucosa (2) served as controls. Estimation of hBD-3 and β-actin gene expression was performed by reverse transcription and realtime PCR. In the nasal and sino-nasal mucosa, only negligible expression levels were detected in 14.29-33.33% of samples, most often in the specimens from the middle nasal passage and ethmoid labyrinth polyps (53.84%), being absent in hypertrophic inferior turbinate. In the middle ear cavity, the frequency detection of the hBD-3 gene expression varied from 7.69% in the stapes superstructures mucosa to 53.85% of the mucosal samples in the presence of cholesteatoma. hBD-3 gene expression was detected in most tissue samples with high microbial contamination: palatine tonsils (100%); adenoid hypertrophy (84.62%); adenoids in hypertrophic states of adenoids and palatine tonsils (87.5%); laryngeal fibrous-vascular polyps (87.5%); other laryngeal pathology (77.78% of the samples). The highest levels of hBD-3 gene expression were found in laryngeal fibrous-vascular polyps. The findings presumed two functionally different types of immune response in mucosa of the ORL organs. In the anatomical-functional areas lined with ciliated epithelium (middle and inferior nasal passages, maxillary and ethmoid sinuses, middle ear), significantly lower frequencies (Fisher's exact test, p < 0.05 to p < 0.001) and levels (Mann-Whitney test, p < 0.05 to p < 0.001) of hBD-3 gene expression were detected, except of polyps of the middle nasal passage and ethmoid labyrinth, and mucosa of the tympanic cavity in cholesteatoma, which may be related to the nature of the pathological process. In the areas lined with squamous epithelium or a combination of squamous and ciliated epithelium, hBD-3 gene expression was detected almost everywhere and at significantly higher levels. In the context of chronic inflammation and infection-related diseases of the ORL organs, in addition to the direct microbicidal activity of hBD-3 as the first line of immune response, one may suggest peptide dysregulation and, even, pathogenetic effects of hBD-3, e.g., increased sensitivity to infections, pathological changes in the composition of the commensal bacteria, fibrous remodeling.